Description : Enzymes functional in cell or mitochondria are (A) Endoenzymes (B) Exoenzymes (C) Apoenzymes (D) Holoenzymes
Last Answer : Answer : A
Description : The cyclooxygenase isoenzymes COX-1 and COX-2 differ from each other in that (a) They catalyse different pathways in prostanoid biosynthesis (b) COX–1 is inhibited by aspirin but not COX–2 (c) COX–2 is inhibited by ibuprofen but not COX–1 (d) COX–1 is constitutive while COX–2 is inducible
Last Answer : Ans: D
Description : Inactive precursors of enzymes are known as (A) Apoenzymes (B) Coenzymes (C) Proenzymes (D) Holoenzymes
Last Answer : Answer : C
Description : Enzymes, which are produced in inactive form in the living cells, are called (A) Papain (B) Lysozymes (C) Apoenzymes (D) Proenzymes
Last Answer : Answer : D
Description : In which of the following types of enzymes an inducer is not required? (A) Inhibited enzyme (B) Cooperative enzyme (C) Allosteric enzyme (D) Constitutive enzyme
Description : A demonstrable inducer is absent in (A) Allosteric enzyme (B) Constitutive enzyme (C) Inhibited enzyme (D) Co-operative enzyme ENZYMES 141
Last Answer : Answer : B
Description : What are constitutive enzymes?
Last Answer : Enzymes whose concentration in a cell is independent of inducer are called constitutive enzymes.
Description : The enzymes encoded by z, y and a genes of lac operon are inducible, and their inducer is (A) Lactose (B) Allo-lactose (C) Catabolite gene activator protein (D) All of these
Description : Enzymes having slightly different molecular structure but performing identical activity are (a) holoenzymes (b) isoenzymes (c) apoenzymes (d) coenzymes.
Last Answer : (b) isoenzymes
Description : Prosthetic groups differ from co-enzymes in that (a) they require metal ions for their activity (b) they (prosthetic groups) are tightly bound to apoenzymes (c) their association with apoenzymes is transient (d) they can serve as co-factors in a number of enzyme-catalyzed reactions.
Last Answer : (b) they (prosthetic groups) are tightly bound to apoenzymes
Description : Which of the following types of drug metabolizing enzymes are inducible: A. Microsomal enzymes B. Nonmicrosomal enzymes C. Both microsomal and nonmicrosomal enzymes D. Mitochondrial enzymes
Last Answer : A. Microsomal enzymes
Description : If all the enzymes, intermediates and cofactors of the citric acid cycle as well as an excess of the starting substrate acetylCoA are present and functional in an organelle free solution at the appropriate ... oxygen (B) Half life of enzyme (C) Turnover of intermediates (D) Reduction of cofactors
Description : Coenzymes combine with (A) Proenzymes (B) Apoenzymes (C) Holoenzymes (D) Antienzymes
Description : Which of the following genes of the E.coli “Lac operon” codes for a constitutive protein? (A) The ‘a’ gene (B) The ‘i’ gene (C) The ‘c’ gene (D) The ‘z’ gene
Description : The gene of lac operon which has constitutive expression is (A) i (B) c (C) z (D) p
Description : An inducer is absent in the type of enzyme: (A) Allosteric enzyme (B) Constitutive enzyme (C) Co-operative enzyme (D) Isoenzymic enzyme
Description : n an inducible operon, the genes are (a) usually not expressed unless a signal turns them”on”. (b) usually expressed unless a signal turns them “off”. (c) never expressed (d) always expresser.
Last Answer : (a) usually not expressed unless a signal turns them”on”.
Description : Enzymes are different from catalysts in (A) Being proteinaceous (B) Not used up in reaction (C) Functional at high temperature (D) Having high rate of diffusion
Description : Plasma non-functional enzymes are (A) totally absent (B) low concentration in plastic (C) important for diagnosis of several disease (D) All of these
Description : What is non-functional enzymes in plasma?
Last Answer : They are coming out from cells due to normal wear and tear.
Description : Enzymes, vitamins and hormones can be classified into a single category of biological chemicals, because all of these (a) help in regulating metabolism (b) are exclusively synthesized in the body of a living organism as at present (c) are conjugated proteins (d) enhance oxidative metabolism.
Last Answer : (a) help in regulating metabolism
Description : The transport of proteins out of the cell is termed exocytosis. Which of the following statement(s) is/are true concerning this process? a. Secretory vesicles fuse with the plasma membrane b. ... or a neurotransmitter d. A decrease in cytoplasmic calcium occurs as part of the secretion process
Last Answer : Answer: a, b, c Transport vesicles that bud off the Golgi network carry both material to be secreted from the cell and protein destined to become components of the plasma ... but may also involve generation of diacylglycerol or production of cyclic AMP which activate kinases or phosphatases
Description : Optical activity is a/an __________ property. (A) Additive (B) Constitutive (C) Both (A) & (B) (D) Neither (A) nor (B)
Last Answer : (C) Both (A) & (B)
Description : The cyclooxygenase isoenzymes COX-1 and COX-2 differ from each other in that: A. They catalyse different pathways in prostanoid biosynthesis B. COX-1 is inhibited by aspirin but not COX-2 C. COX-2 is inhibited by ibuprofen but not COX-1 D. COX-1 is constitutive while COX-2 is largely
Last Answer : D. COX-1 is constitutive while COX-2 is largely
Description : Explain an inducible operon. -Biology
Last Answer : answer:
Description : Why is the lac operon said to be an inducible operon? -Biology
Description : The distinctive feature of the isoenzyme cyclooxygenase-2 is (a) It is not inhibited by indomethacin (b) It is inducible (c) It generates cytoprotective prostagladins in gastric mucosa (d) It is found only in foetal tissues
Last Answer : Ans: B
Description : Aspirin in low doses produces longlasting inhibition (a) Platelets contain low quantity of COX (b) Platelets cannot synthesize fresh COX molecules (c) Platelets bind aspirin with high affinity (d) Platelet COX is inducible
Description : .Gene regulation governing lactose operon of E.coli that involves the lac I gene product is (a) negative and repressible because repressor protein prevents transcription (b) feedback inhibition ... be induced by lactose (d) negative and inducible because repressor protein prevents transcription.
Last Answer : (d) negative and inducible because repressor protein prevents transcription.
Description : The lac operon is an example of (a) repressible operon (b) overlapping genes (c) arabinose operon (d) inducible operon.
Last Answer : (d) inducible operon.
Description : Gene regulation governing lactose operon of E.coli that involves the lac I gene product is (a) negative and repressible because repressor protein prevents transcription (b) feedback inhibition ... be induced by lactose (d) negative and inducible because repressor protein prevents transcription.
Description : An example of an inducible group of genes is the ______. a. ARG operon b. NAC operon c. LAC operon d. SAC operon
Last Answer : c. LAC operon
Description : Acquisition of inducible energy dependent efflux proteins by bacteria serves to: A. Secrete exotoxins B. Enhance virulance C. Lyse host tissue D. Confer antibiotic resistance
Last Answer : D. Confer antibiotic resistance
Description : The distinctive feature of the isoenzyme cyclooxygenase-2 is: A. It is not inhibited by indomethacin B. It is inducible C. It generates cytoprotective prostagladins in gastric mucosa D. It is found only in foetal tissues
Last Answer : B. It is inducible
Description : Aspirin in low doses produces longlasting inhibition of platelet cyclooxygenase (COX) because: A. Platelets contain low quantity of COX B. Platelets cannot synthesize fresh COX molecules C. Platelets bind aspirin with high affinity D. Platelet COX is inducible
Last Answer : B. Platelets cannot synthesize fresh COX molecules
Description : Which one of the following terms describes not only the physical space occupied by an organism, but also its functional role in the community of organisms? (1) Eco-niche (2) Ecosystem (3) Ecotone (4) Habitat
Last Answer : (2) Ecosystem Explanation: An ecosystem is a community of living organisms in conjunction with the nonliving components of their environthent, interacting as a system. The nature of the organisms-the ... individuals are capable of carrying out, and the relative efficiency with which they do so.
Description : Niche is (a) all the biological factors in the organism’s environment (b) the physical space where an organism lives (c) the range of temperature that the organism needs to live (d) the functional role played by the organism where it lives.
Last Answer : (d) the functional role played by the organism where it lives.
Description : Niche is (1) all the biological factors in the organism environment (2) the physical space where an organism live (3) the range of temperature that the organism needs to live (4) the functional role played by the organism where it lives
Last Answer : (4) the functional role played by the organism where it lives
Description : Which one of the following terms describes not only the physical space occupied by an organism, but also its functional role in the community of organisms ? (1) Eco-niche (2) Ecosystem (3) Ecozone (4) Habitat
Last Answer : Ecosystem
Description : If for some reason the parietal cells of the gut epithelium become partially non-functional, what is likely to happen? (a) The pancreatic enzymes and specially the trypsin and lipase will ... more effective. (d) Proteins will not be adequately hydrolysed by pepsin into proteoses and peptones.
Last Answer : (d) Proteins will not be adequately hydrolysed by pepsin into proteoses and peptones.
Description : The process of self-digestion of selective non-functional organelles by a cell through the action of enzymes originating within the cell is referred to as (A) Pinocytosis (B) Endocytosis (C) Autophagy (D) Cytotoxicity
Last Answer : (C) Autophagy
Description : Enzymes which exist in multiple forms within single specing of an organism
Last Answer : Ans. Isoenzyme
Description : Enzymes are A- organic compounds produced by living organism B- .inorganic compounds C- organic as well as inorganic compounds D- all of these
Last Answer : organic compounds produced by living organism
Description : Coenzyme is (A) Often a vitamin (B) Always an inorganic compound (C) Always a protein (D) Often a metal ENZYMES 173
Description : Which of the following is present as a marker in lysosomal enzymes to direct them to their destination? (A) Glucose-6-phosphate (B) Mannose-6-phosphate (C) Galactose-6-phosphate (D) N-Acetyl neuraminic acid
Description : Ribozymes are (A) Enzymes present in ribosomes (B) Enzymes which combine the ribosomal subunits (C) Enzymes which dissociate (D) Enzymes made up of RNA
Description : The enzymes present in the membrane of mitochondria are (A) Flavoproteins and cytochromes (B) Fumarase and lipase (C) Enolase and catalase (D) Hexokinase and zymase
Description : Out of the total enzymes present in a cell, a mitochondrion alone has (A) 4% (B) 70% (C) 95% (D) 50%
Description : Enzymes catalyzing electron transport are present mainly in the (A) Ribosomes (B) Endoplasmic reticulum (C) Lysosomes (D) Inner mitochondrial membrane
Last Answer : D